An ancient Greek "computer" used to calculate the movements of the sun, moon and planets has been linked to Archimedes after scientists deciphered previously hidden inscriptions on the device.

X-ray images of the bronze mechanism, which was recovered from a shipwreck more than a century ago, also revealed a sporting calendar that displays the cycle of the prestigious "crown" games, including the Olympics, which were held every four years.

The remarkably complex machine has been dated to around 150 BC, but it has puzzled researchers who have spent decades examining its 80 or so corroded fragments in the hope of learning how it worked and perhaps even who made it.

The device is thought to be the earliest known mechanism to use geared wheels, a feat of engineering that was not to reappear for at least another thousand years in the astronomical clocks of medieval Europe.

Writing in the latest issue of the journal Nature, researchers from Britain and the US describe how they used three-dimensional X-ray imaging to decipher previously unnoticed inscriptions on the back of the device, which was enclosed in a wooden casing the size of a large dictionary.

The images revealed the names of the different months, which were used only in certain parts of north western Greece and Sicily. Intriguingly, it is the same calendar that would have been used in Syracuse, the Sicilian city and home to the great mathematician Archimedes, who is known from ancient texts to have built astronomical machines.

"We know Archimedes did mechanical astronomy here 100 years earlier and this could be from his home city, it could have been inspired by his work, or it could have been a local tradition that he started," said Alexander Jones from the Institute for the Study of the Ancient World at New York University, who examined the fragments with British researchers John Steele and Tony Freeth.

The mechanism is likely to have survived only through the good fortune of being aboard the ill-fated vessel, since bronze and other metals at the time were frequently melted down to make other objects when they fell into disrepair or were no longer needed.

"There must have been an unbroken tradition of craftsmen doing this kind of work, but they didn't write it down in books for the most part, they were teaching through workshops and appreticeships, so we're not going to get much other evidence," Jones added.

Further images of the mechanism revealed a previously unknown sporting calendar that marked the times of the Olympiad cycle, naming the prominent Nemean, Isthmian, Pythian and Olympic games. The events were so popular that truces were often called in times of war to allow people safe passage to attend them.

The unexpected discovery of the sporting calendar suggests the device was more than a mere tool for teaching and popularising the workings of the cosmos. "The machine as a whole was not just showing high science, showing astronomy, but was linking science to the cultural cycles of the Greeks," said Jones.

The machine, which was probably driven by a hand-operated crank, used a collection of inter-meshing gears to calculate the positions of the sun and moon, the dates of eclipses, and possibly the positions of the five planets known about at the time. "Our idea of what ancient astronomy was doing at the time is very much a patchwork of fragmentary bits of evidence that start fitting together when we relate them to this," said Jones.